Pregnant mice (CD-1 strain) were exposed to 2.45 GHz microwave radiation at a power density level of 30 mW/cm squared. At exposure to 30 mW/cm squared (SAR = about 32 mW/g) during days 1-6 a significant decrease in implantation sites per litter and average fetal weight was observed. Exposure to 30 mW/cm squared during days 6-15 resulted in a slight increase in the number of malformed fetuses but was not statistically significant as obtained in a previous experiment. This repeat of previous work again indicates that the threshold for teratogenic effects in the CD-1 mouse strain is approximately 30 mW/cm squared.